condition mean min max ZT0-3 1.5 1.5 1.5 ZT4-7 2.2 2.2 2.2 ZT8-11 16.7 16.7 16.7 ZT12-15 8.85 8.85 8.85 ZT16-19 3.8 3.8 3.8 ZT20-23 12.45 12.45 12.45